Something I have done in the past. I had a 2-liter of water that was connected to a line, that also connected to my release keys. The keys also had a weight on them, so when the bottle is empty, the key would be released, or lowered down so I can get free.

To make this last a very long time, you can freese 1/2 liter and fill the rest with cold water. You must dring almost all of the water to get free.

Of course, the first liter is easy, but you will have to wait till the second liter melts. In the mean time, you will need to "GO" and if you like tubes as much as our host does, the pee can go back into the bottle to melt the frosen water. Of courst, you'll have to drink all of the water, and pee to get the key to drop so you can get free.

Another note. We have a device for bed wetters. it works on salts that comes from pee. clear water does nothing. With this, one can set up a few toys that could make your sesion a bit interesting when you pee.

So, here is how it works. A cord with keys on the end, is frosen in a 2-liter bottle 1/2 full of water. The last 1 liter is cold water. A piss condom has a tube connected to fill the bottle when you pee. The pee turns on your toys as it melts the ice. You will have to wait till the ice melts before you can drink it all. This will make the bottle light, and the keys will drop down and you can get free.